Scilab Function
Last update : 16/12/2004

plot3d1 - 3D gray or color level plot of a surface

### Calling Sequence

  `plot3d1(x,y,z,[theta,alpha,leg,flag,ebox])`
  `plot3d1(xf,yf,zf,[theta,alpha,leg,flag,ebox])`
  ``
  `plot3d1(x,y,z,<opts_args>)`
  `plot3d1(xf,yf,zf,<opts_args>)`

### Parameters

- `x,y`: row vectors of sizes n1 and n2 (x-axis and y-axis coordinates). These coordinates must be monotone.
- `z`: matrix of size (n1,n2). `z(i,j)` is the value of the surface at the point (x(i),y(j)).
- `xf,yf,zf`: matrices of size (nf,n). They define the facets used to draw the surface. There are `n` facets. Each facet `i` is defined by a polygon with `nf` points. The x-axis, y-axis and z-axis coordinates of the points of the ith facet are given respectively by `xf(:,i)`, `yf(:,i)` and `zf(:,i)`.
- `<opt_args>`: This represents a sequence of statements `key1=value1, key2=value2`,... where `key1`, `key2,...` can be one of the following: theta, alpha ,leg,flag,ebox (see definition below).
- `theta, alpha`: real values giving in degree the spherical coordinates of the observation point.
- `leg`: string defining the labels for each axis with @ as a field separator, for example "X@Y@Z".
- `flag`: a real vector of size three. `flag=[mode,type,box]`.
  - `mode`: an integer (surface color).
    - `mode>0`: the surface is painted with color `"mode"` ; the boundary of the facet is drawn with current line style and color.
    - `mode=0:`a mesh of the surface is drawn.
    - `mode<0:`the surface is painted with color `"-mode"` ; the boundary of the facet is not drawn.

      Note that the surface color treatement can be done using `color_mode` and `color_flag` options through the surface entity properties (see `surface_properties`).

  - `type`: an integer (scaling).
    - `type=0:`the plot is made using the current 3D scaling (set by a previous call to `param3d`, `plot3d`, `contour` or `plot3d1`).
    - `type=1:`rescales automatically 3d boxes with extreme aspect ratios, the boundaries are specified by the value of the optional argument `ebox`.
    - `type=2:`rescales automatically 3d boxes with extreme aspect ratios, the boundaries are computed using the given data.
    - `type=3:`3d isometric with box bounds given by optional `ebox`, similarily to `type=1`.
    - `type=4:`3d isometric bounds derived from the data, to similarily`type=2`.
    - `type=5:`3d expanded isometric bounds with box bounds given by optional `ebox`, similarily to `type=1`.
    - `type=6:`3d expanded isometric bounds derived from the data, similarily to `type=2`.

      Note that axes boundaries can be customized through the axes entity properties (see `axes_properties`).

  - `box`: an integer (frame around the plot).
    - `box=0:`nothing is drawn around the plot.
    - `box=1:`unimplemented (like box=0).
    - `box=2:`only the axes behind the surface are drawn.
    - `box=3:`a box surrounding the surface is drawn and captions are added.
    - `box=4:`a box surrounding the surface is drawn, captions and axes are added.

      Note that axes aspect can also be customized through the axes entity properties (see `axes_properties`).

- `ebox`: It specifies the boundaries of the plot as the vector `[xmin,xmax,ymin,ymax,zmin,zmax]`. This argument is used together with `type` in `flag` : if it is set to `1`, `3` or `5` (see above to see the corresponding behaviour). If `flag` is missing, `ebox` is not taken into acoount.

  Note that, when specified, the `ebox` argument acts on the `data_bounds` field that can also be reset through the axes entity properties (see `axes_properties`).

### Description

`plot3d1` plots a surface with colors depending on the z-level of the surface. This special plot function can also be enabled setting `color_flag=1` after a `plot3d` (see `surface_properties`)

Enter the command `plot3d1()` to see a demo.

### Examples

    // simple plot using z=f(x,y)
    t=[0:0.3:2*%pi]'; z=sin(t)*cos(t');
    plot3d1(t,t,z)
    // same plot using facets computed by genfac3d
    [xx,yy,zz]=genfac3d(t,t,z);
    clf();
    plot3d1(xx,yy,zz)
    // multiple plots
    clf();
    plot3d1([xx xx],[yy yy],[zz 4+zz])
    // simple plot with viewpoint and captions
    clf() ;
    plot3d1(1:10,1:20,10*rand(10,20),35,45,"X@Y@Z",[2,2,3])
    // same plot without grid
    clf()
    plot3d1(1:10,1:20,10*rand(10,20),35,45,"X@Y@Z",[-2,2,3])
    // plot of a sphere using facets computed by eval3dp
    deff("[x,y,z]=sph(alp,tet)",["x=r*cos(alp).*cos(tet)+orig(1)*ones(tet)";..
    "y=r*cos(alp).*sin(tet)+orig(2)*ones(tet)";..
    "z=r*sin(alp)+orig(3)*ones(tet)"]);
    r=1; orig=[0 0 0];
    [xx,yy,zz]=eval3dp(sph,linspace(-%pi/2,%pi/2,40),linspace(0,%pi*2,20));
    clf()

    plot3d(xx,yy,zz)
    e=gce();
    e.color_flag=1;
    scf(2);
    plot3d1(xx,yy,zz) // the 2 graphics are similar

### See Also

`plot3d`, `gca`, `gce`, `scf`, `clf`,

### Author

J.Ph.C.